Video instructions improve accuracy of self-measures of waist circumference compared with written instructions

摘要

ObjectiveTo determine whether video-based instructions improve the accuracy of self-measures of waist and hip circumference compared with written instructions.DesignPopulation-based, cross-sectional study. Self-measurements of waist circumference (WC) and hip circumference (HC) of fifty-seven participants randomly allocated to receive either written instruction or video instruction were compared with those of a trained technician.SettingAberdeen, Scotland, and Brussels, Belgium, between February and April 2010.SubjectsAdults aged 18a€“62 years with a high level of English language and no prior training in anthropometry.ResultsWC was significantly overestimated by the written method (1?·75 cm bias; P = 0?·007) but not the video method (0?·95 cm bias; P = 0?·239). HC was significantly underestimated in both written (a?’0?·35 cm bias; P = 0?·009) and video methods (a?’0?·75 cm bias; P = 0?·046). Reliability was not significantly affected by age, sex, BMI or WC. Blanda€“Altman plots demonstrated wide limits of agreement for WC (a?’6?·83, 6?·08 cm for written method; a?’10?·14, 6?·72 cm for video method) and HC (a?’12?·85, 1?·60 cm for written method; a?’10?·82, 2?·50 cm for video method).ConclusionsVideo technology can support more accurate self-measurements of anthropometric data in epidemiological studies. Further research is warranted using larger and more heterogeneous samples in order that results can be generalised.